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  <title>Returns the number of arguments passed to the function</title>
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  <div id="layout-content"><div id="function.func-num-args" class="refentry">
 <div class="refnamediv">
  <h1 class="refname">func_num_args</h1>
  <p class="verinfo">(PHP 4, PHP 5, PHP 7)</p><p class="refpurpose"><span class="refname">func_num_args</span> &mdash; <span class="dc-title">Returns the number of arguments passed to the function</span></p>

 </div>
 
 <div class="refsect1 description" id="refsect1-function.func-num-args-description">
  <h3 class="title">说明</h3>
  <div class="methodsynopsis dc-description">
   <span class="methodname"><strong>func_num_args</strong></span>
    ( <span class="methodparam">void</span>
   ) : <span class="type">int</span></div>

  <p class="para rdfs-comment">
   Gets the number of arguments passed to the function.
  </p>
  <p class="para">
   This function may be used in conjunction with 
   <span class="function"><a href="func_get_arg.html" class="function">func_get_arg()</a></span> and <span class="function"><a href="func_get_args.html" class="function">func_get_args()</a></span>
   to allow user-defined functions to accept variable-length argument lists.
  </p>
 </div>


 <div class="refsect1 returnvalues" id="refsect1-function.func-num-args-returnvalues">
  <h3 class="title">返回值</h3>
  <p class="para">
   Returns the number of arguments passed into the current user-defined
   function.
  </p>
 </div>


 <div class="refsect1 changelog" id="refsect1-function.func-num-args-changelog">
  <h3 class="title">更新日志</h3>
  <p class="para">
   <table class="doctable informaltable">
    
     <thead>
      <tr>
       <th>版本</th>
       <th>说明</th>
      </tr>

     </thead>

     <tbody class="tbody">
      <tr>
       <td>5.3.0</td>
       <td>
        This function can now be used in parameter lists.
       </td>
      </tr>

      <tr>
       <td>5.3.0</td>
       <td>
        If this function is called from the outermost scope of a file
        which has been included by calling <span class="function"><a href="include.html" class="function">include</a></span>
        or <span class="function"><a href="require.html" class="function">require</a></span> from within a function in the
        calling file, it now generates a warning and returns -1.
       </td>
      </tr>

     </tbody>
    
   </table>

  </p>
 </div>


 <div class="refsect1 errors" id="refsect1-function.func-num-args-errors">
  <h3 class="title">错误／异常</h3>
  <p class="para">
   Generates a warning if called from outside of a user-defined function.
  </p>
 </div>


 <div class="refsect1 examples" id="refsect1-function.func-num-args-examples">
  <h3 class="title">范例</h3>
  <p class="para">
   <div class="example" id="example-6204">
    <p><strong>Example #1 <span class="function"><strong>func_num_args()</strong></span> example</strong></p>
    <div class="example-contents">
<div class="phpcode"><pre><span style="color: #000000">
<span style="color: #0000BB">&lt;?php<br /></span><span style="color: #007700">function&nbsp;</span><span style="color: #0000BB">foo</span><span style="color: #007700">()<br />{<br />&nbsp;&nbsp;&nbsp;&nbsp;</span><span style="color: #0000BB">$numargs&nbsp;</span><span style="color: #007700">=&nbsp;</span><span style="color: #0000BB">func_num_args</span><span style="color: #007700">();<br />&nbsp;&nbsp;&nbsp;&nbsp;echo&nbsp;</span><span style="color: #DD0000">"Number&nbsp;of&nbsp;arguments:&nbsp;</span><span style="color: #0000BB">$numargs</span><span style="color: #DD0000">\n"</span><span style="color: #007700">;<br />}<br /><br /></span><span style="color: #0000BB">foo</span><span style="color: #007700">(</span><span style="color: #0000BB">1</span><span style="color: #007700">,&nbsp;</span><span style="color: #0000BB">2</span><span style="color: #007700">,&nbsp;</span><span style="color: #0000BB">3</span><span style="color: #007700">);&nbsp;&nbsp;&nbsp;<br /></span><span style="color: #0000BB">?&gt;</span>
</span>
</pre></div>
    </div>

    <div class="example-contents"><p>以上例程会输出：</p></div>
    <div class="example-contents screen">
<div class="cdata"><pre>
Number of arguments: 3
</pre></div>
    </div>
   </div>
  </p>
  <p class="para">
   <div class="example" id="example-6205">
    <p><strong>Example #2 <span class="function"><strong>func_num_args()</strong></span> example before and
    after PHP 5.3</strong></p>
    <div class="example-contents">
<div class="phpcode"><pre><span style="color: #000000">
test.php<br /><span style="color: #0000BB">&lt;?php<br /></span><span style="color: #007700">function&nbsp;</span><span style="color: #0000BB">foo</span><span style="color: #007700">()&nbsp;{<br />&nbsp;&nbsp;&nbsp;&nbsp;include&nbsp;</span><span style="color: #DD0000">'./fna.php'</span><span style="color: #007700">;<br />}<br /><br /></span><span style="color: #0000BB">foo</span><span style="color: #007700">(</span><span style="color: #DD0000">'First&nbsp;arg'</span><span style="color: #007700">,&nbsp;</span><span style="color: #DD0000">'Second&nbsp;arg'</span><span style="color: #007700">);<br /></span><span style="color: #0000BB">?&gt;<br /></span><br />fna.php<br /><span style="color: #0000BB">&lt;?php<br /><br />$num_args&nbsp;</span><span style="color: #007700">=&nbsp;</span><span style="color: #0000BB">func_num_args</span><span style="color: #007700">();<br /></span><span style="color: #0000BB">var_export</span><span style="color: #007700">(</span><span style="color: #0000BB">$num_args</span><span style="color: #007700">);<br /><br /></span><span style="color: #0000BB">?&gt;</span>
</span>
</pre></div>
    </div>

    <div class="example-contents"><p>
     Output previous to PHP 5.3:
    </p></div>
    <div class="example-contents screen">
<div class="cdata"><pre>
2
</pre></div>
    </div>
    <div class="example-contents"><p>
     Output in PHP 5.3 and later will be something similar to:
    </p></div>
    <div class="example-contents screen">
<div class="cdata"><pre>
Warning: func_num_args():  Called from the global scope - no function
context in /home/torben/Desktop/code/ml/fna.php on line 3
-1
</pre></div>
    </div>
   </div>
  </p>
 </div>


 <div class="refsect1 notes" id="refsect1-function.func-num-args-notes">
  <h3 class="title">注释</h3>
  <blockquote class="note"><p><strong class="note">Note</strong>: <p class="para">因为函数依赖于当前作用域以确定参数的细节，所以在
5.3.0 以前的版本中不能用作函数的参数。如必须传递此值时，可将结果赋与一个变量，然后用此变量进行传递。</p></p></blockquote>
 </div>


 <div class="refsect1 seealso" id="refsect1-function.func-num-args-seealso">
  <h3 class="title">参见</h3>
  <p class="para">
   <ul class="simplelist">
    <li class="member"><span class="function"><a href="func_get_arg.html" class="function" rel="rdfs-seeAlso">func_get_arg()</a> - 返回参数列表的某一项</span></li>
    <li class="member"><span class="function"><a href="func_get_args.html" class="function" rel="rdfs-seeAlso">func_get_args()</a> - 返回一个包含函数参数列表的数组</span></li>
    <li class="member"><span class="methodname"><a href="reflectionfunctionabstract.getnumberofparameters.html" class="methodname" rel="rdfs-seeAlso">ReflectionFunctionAbstract::getNumberOfParameters()</a> - 获取参数数目</span></li>
   </ul>
  </p>
 </div>


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